The present invention relates to a process for rolling a drum with a photosensitive film in a duplicating machine or similar device.
According to the present invention, it becomes possible to easily roll a photosensitive film around a drum with a suitable tension and it becomes possible to easily maintain the weight balance of the drum.
This invention achieves this objective. By making the photosensitive film tubular by uniting the seam-edge parts on both sides of the photosensitive film through a thermally contractible film. The drum is there rolled without any slippage of the photosensitive film by causing the thermally contractible film to contract by heating same.
In prior photosensitive drums used in duplicating machines, the surface of the drum has been directly given an OPC coating in the past. Since the drum having such coating is heavy and difficult to handle, this method was suitable for small-sized drums.
This problem has been met initially by various methods for rolling the drum with a photosensitive film. Prior methods for rolling the drum with the photosensitive film not only elevates the cost by making the structure of the drum more complicated but it becomes difficult to roll the drum with the photosensitive film at a predetermined tensile force. In some cases, there develops a problem of creating wrinkles in the photosensitive film. This problem becomes all the more conspicuous at the time when a large-sized photosensitive drum is to be formed.
In the aforementioned process, further, the weight balance of the drum is destroyed by the groove which is used to attach the film with the result that it is necessary to install a balancer or create a special shape in order to achieve balancing.
The present invention was made in the light of the aforementioned problems.